I spent waaaaaaaay too many hours last night trying to make a nicer European style motorway exit. As anyone who has played vanilla/console knows, the game doesn't let you curve roads in their natural, realistic direction off existing curved roads and it also snaps to nearby nodes even with all snapping off, so you can't get too close to an existing node.
Which in short means if you build a roundabout style exit your junctions are always going to look something like this, it doesn't look nice with the kinks and it does also slow cars down. The roundabout itself also ends up bigger than it should be.
I therefore decided to do some experimenting and found firstly a fully round circle isn't good. I also wanted the roundabout to be on ground level, not raised. After much trial and error I ended up with a base like this. The little roads in the middle of the curve are just guides for the centre.
Even to get to that stage takes a bit of manipulation of roads and land. The key generally is to build with dirt or smallest tarmac road and upgrade. You can do things that it won't allow you if you start with highways/wider roads.
So as I said at this stage if you try and curve off some natural off ramps the game won't let you. I figured since I already have the start of the curve there what If I delete the original bend, build natural curves and then try to join them somehow.
Again using dirt roads, and other dirt roads for grid guides. Not perfect, but not bad. At this stage though I wasn't sure if the game would allow me to make the curves I wanted to join them, it usually doesn't. It did though, thanks to using dirt roads. Then I had to just join up to the exit roads which again isn't easy, the game always wants to curve roads the opposite to the way you want. So the exits are still longer and jankier than I'd hoped.
This is what happens whatever you do trying to curve them naturally. First one fine, second one always curves the wrong way, so no good.
Final thing was to curve the bridges over the motorway, uprade everything and this is the nearly final result
It's still a bit rough and not totally symmetrical despite my best efforts being precise with the freeform roads but I think it's about as good as you'll get on console/vanilla. You may also note that only the two bridges are actually bridge roads, despite the entire thing being bridges to start with including the ramps. Another trick, if you build bridges but then lift the land back up to the exact height, when you upgrade the road it'll switch to a normal road.
I think with a bit of decoration, trees and bushes to hide the janky bits, it'll look pretty nice. I just hope the traffic works on it, otherwise it's hours wasted!